The simulation of dislocation dynamics in single crystals of hexagonal close-packed metal was studied, with particular regard to the hardening which was associated with prismatic slip at low temperatures. Two original aspects of the simulation method were the treatment of the hexagonal close-packed lattice by using an orthorhombic representation, and the use of periodic boundary conditions. The mobilities of screw and non-screw segments were defined in a phenomenological manner. Investigations of the interactions between dislocations, gliding on different prismatic planes, showed that no junction was formed between intersecting screw dislocations. This resulted in rather small forest hardening at low temperatures. This explained experimental observations of an initial deformation stage, with a low strain-hardening coefficient, in Zr and Ti crystals at low temperatures.

Dislocation Study of Prismatic Slip Systems and their Interactions in Hexagonal Close Packed Metals - Application to Zirconium. G.Monnet, B.Devincre, L.P.Kubin: Acta Materialia, 2004, 52[14], 4317-28